


Deep Resevoirs

by goresque



Category: Transformers - All Media Types
Genre: Aftercare, BDSM, Breeding, Knotting, Master/Pet, Other, cumflation
Language: English
Status: Completed
Published: 2018-10-27
Updated: 2019-02-15
Packaged: 2019-08-08 08:05:17
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,512
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16425590
Author URL: https://archiveofourown.org/users/goresque/pseuds/goresque
Summary: Optimus finds a new way to train his unruly pet.Chapter 2: now with aftercare





	1. Chapter 1

**Author's Note:**

> This is my contribution to kinktober. It took me all month to write.

Optimus wrapped the chain twice around his servo where he stood over his pet. He held it with a small amount of slack, and stood ready to pull it taut should the mech below him become unruly. 

At Optimus’s pedes, Megatron sat on his knees. A muzzle in the shape of a turbohound’s snout was strapped around his helm, matching the collar around his throat. He held his servos behind his back with trained diligence, ready to act should Optimus command it. His broad pauldrons flexed, displaying his own restraint. There was no doubt in Optimus’s mind that his pet could break his bonds; the real fun came in challenging him not to.

“You’ve not been listening,” Optimus rumbled. His tone dipped as one hand slid across Megatron’s jaw, his thumb stroking a gentle pattern into the hot metal. “How am I to trust you with my protection if I cannot trust you to fulfill simple commands?”

The powerful engine within Megatron’s frame revved, a dull roar against the backdrop of silence surrounding them. No sooner did Optimus wrap another length of the chain around his wrist, pulling it taut. Megatron leered as he was forced to arch his neck. 

The power struggle was short lived. Megatron’s engine settled, and Optimus allowed the chain to fall slack once more. Their body language resumed neutrality. The grey mech held firm control of his frame, every cable and platelet kept in line. 

“I will train your obedience, and your stamina tonight.” 

Megatron didn’t flinch as Optimus leaned down, servo sliding between his thighs. He thumbed the seam along the top of Megatron’s modesty panel, and clicked his tongue in disappointment, “I’ve told you to keep yourself open to me when we play. Pets don’t have modesty. Open.”

Once the command was uttered, Megatron obeyed. His engine purred as Optimus stroked along the length of his valve, and then teased the edges of his spike housing. The stroke of thick fingers sliding between his sensitive mesh made a trail of slick up the middle of his array.

“Spike out.”

A grunt left Megatron as his black spike sluggishly pushed out of its housing. The red biolights that blinked a fading line up the underside of his shaft pulsed an eerie red glow against his gray thighs. Each light sat between an apex of plating, creating ridges at each layer; Optimus stroked a digit up the line of lights. He didn’t miss the way Megatron clenched his jaw.

Once his spike was fully pressurized, Optimus gripped him by the base, and produced a magnaring from his subspace. He secured it around Megatron’s shaft, ignoring the drawn out groan it brought from his pet.

“This will ensure you stay pressurized throughout your training,” Optimus said. He stroked along the edge of the ring, teasing out twitches from his stony pet. Optimus studied his pet with diligence, checking him over for signs of distress or pain. A strict owner he may be, but he refused to be cruel.

“Now…” Optimus made a show of circling Megatron, observing him and making sure he was at attention. He raised the leash as we went accordingly, as if it were second nature for the comfort of his pet. He gave Megatron a slight nudge with his pede as his pet’s posture slouched just barely. “At attention. I have a very important task for you. To the breeding bench.”

Optimus watched Megatron stiffen at his command. He didn’t give his pet a chance to disobey, pulling him by his leash to the aforementioned piece of furniture. 

It wasn’t terribly conspicuous. It was black and smooth, the softer metals of it meant to be gentle against the kibble. Optimus didn’t chide his pet for being wary; the breeding bench had been a source of punishment in sessions past. This time, however, it would play host to a different activity.

When they were before the bench, Optimus turned around and curled his servos around Megatron’s muzzle, thumbing the latches. “I will remove this for your training, however,” Optimus’s servo moved to squeezed the snout, soliciting a low whine from his pet, “If you bite, it will be replaced. You are permitted to speak, since I have removed it.”

Upon releasing Megatron, he set the muzzle to the side of the bench. Optimus saw his pet waiting to be ordered to bend over the offending piece of furniture, as he had been ordered to do before every other time they’d used the equipment. Instead, Optimus turned around and knelt, resting his torso against the bench. The Prime spread his knees apart as his modesty panel transformed away to reveal his wetware, already glistening with slick.

Moments without action passed, and Optimus glanced over his shoulder to gauge his pet’s body language. 

Megatron was leering. His spike was achingly rigid against his pelvis, a hunger in his optics. Yet he took no lead. Optimus tugged on the chain to gain his attention, and when he did so Megatron’s gaze locked with his own.

“You will mount me,” Optimus rumbled, not allowing his own arousal to color his words, lest he show any vulnerability, “And you will not cease until your transfluid reservoirs have been emptied.”

There was still no movement, until Optimus gave another pull on the chain. Only when he felt servos curl around his hips did he relax into the bench, his thighs spreading wider. Megatron’s full weight leaned into him then, bearing down on him with the length of his frame.

“Anything to say?” Optimus murmured, a full frame rattle coming over him as he felt Megatron’s venting against him. Megatron was normally silent during their sessions, regardless if he was gagged or not, so it came as no surprise his pet still hadn’t uttered a word. Reaching out was one of the only ways that Optimus’s could gauge Megatron’s immersion.

“No, Master,” Megatron vented out, pressing his hips firmly against Optimus’s aft. The erotic slide of Megatron’s spike between his thighs had Optimus stifling a moan, barely contained behind his battle mask. He could feel the girth of his pet prising between the swollen lips of his valve, the pierced head nudging his anterior node whenever Megatron jerked his hips reminiscent of an actual beast.

Arousal bled from Megatron’s field as he rutted, never truly penetrating his Prime. Every buck of his hips was met with a soft whine from Optimus as his anterior node was stabbed, prompting him to finally reach back and squeeze his pet’s spike in hand, to guide him to the fluttering entrance of his valve.

As soon as he hit home, Megatron pistoned into a brutal pace. He clasped his wrists against Optimus’s sides, his servos curled into fists. Every thrust in, never fully pulling out, brought a surprised shout from the Prime. Every undignified noise had Megatron rumbling with the satisfaction that he could make Optimus Prime himself come undone.

“Good- good pet.” Optimus’s vocalizer bleated static between words. His frame rocked forward with each rapid thrust, the bench creaking under the sheer power of Megatron’s movement. Optimus yanked the chain around his fist once more, his actions smooth and rapid. “You may not engage your knot; not until you’ve emptied your reserves.”

Megatron’s growl echoed in his audials. Optimus howled as his pet jerked his hips with the fierceness becoming of a warlord, his valve clenching and throbbing around the pulsing spike inside it. Every thrust pushed the swelling knot of Megatron’s mod against the rim of his valve. The pressure of it had Optimus’s frame crackling into an explosive overload, the blue electricity arcing over his trembling plating. 

The clench and cycle of Optimus’s sopping valve had Megatron roaring an overload behind him. His hips creaked with the effort it took to keep him moving. Megatron’s thrusts slowed to lazy rocking, until his knot rested against Optimus’s valve and his body pressed along the Prime’s.

His rest was interrupted by his helm forced up by his leash.

“You were not permitted to rest, Pet,” Optimus growled. He pressed his hips back, pushing back on the swollen knot resting at the end of Megatron’s spike. The pressure had his pet flinching back, only to be jerked by the leash. “Continue.”

The hollow whine didn’t escape Optimus. Even so, his pet moved once more, his still aching spike following the erotic slide and pull of Optimus’s hips. Megatron’s thrusts were sluggish, but he obeyed.

Megatron felt as if their earlier roles had been reversed. His momentary triumph at undoing his Prime was turned out by Optimus’s utter mastery of his body. The first overload had taken the fight out of Megatron, left the door open for Optimus to take complete control of him. Every push into the Prime had his spike burning with sensation.

“Is that all you have, pet?” Optimus rumbled, jerking the leash once more. “I know there is more power in you. I did not tame a domestic animal, Megatron. Where is my fiery pet I struggled to subdue?”

The taunt smoldered in Megatron’s tanks. His answer came in a gutteral, animalistic growl. His thrusts picked up speed and power, grinding his hips every time their frames connected. Once more he drew out Optimus’s squealing gears and helpless moans, and euphoria washed over him as he felt his master’s valve spasm around him. He grunted through his thrusts, chasing another overload that remained just out of reach.

Another overload rippled through Optimus’s frame. Megatron roared his frustration, his fists sliding up Optimus’s back to hold his pauldrons. He used the leverage he gained to drive his thrusts harder, prompting a surprised cry from Optimus. As his master overloaded a fourth time, Megatron finally tipped with him, their combined charge bursting into crackling electricity along their plating.

Transfluid spilled around Megatron’s spike. He moaned as the slop spilled between them, falling to the ground and spilling onto the breeding bench. Every thrust forward prompted a deafening squelch. As he pulled out, Megatron watched his transfluid slide down Optimus’s silver thighs, and was overcome with the desire to kneel and suck him clean. When he moved to feed his desires, he was stalled by a strong servo grasping his spike and his leash going taut.

“Did I say you could stop?” Optimus snarled. The harsh words from his master hand Megatron lining right back up to penetrate him. He shuddered as the wet heat of Optimus’s channel swallowed him again.

Another overload from Optimus. Megatron was weakening. His second wind had been enough to gather him through his second overload, and he wasn’t entirely sure he would make it to a third. His spike was overstimulated, burning within the confines of Optimus’s valve. He trembled as he leaned his frame over top of Optimus’s nestling his faceplate between Optimus’s pauldron and his neck. A quick check to his transfluid tanks showed him he had only emptied forty percent of his reserves. On top of that, every overload dispersed less transfluid.

“Master,” Megatron rasped, his frame trembling with the sensation of Optimus’s valve clenching coming over him. “Permission to speak?”

“Speak, pet.”

“I do not have the strength to continue my training. May we cease? Or take a break?” Megatron felt small, even atop Optimus and dwarfing him with his bulk. He felt weak, for being unable to continue.

Optimus’s engine rumbled. Megatron couldn’t tell if it were from displeasure or not. “If we cease your training, you will not receive its full benefits. Not only that, you will be disappointed and unfulfilled that you could not meet my expectations. You will drop.”

Megatron’s plating rattled as he nodded. He knew Optimus was right. His own pride would be his downfall at the end of their session. “Are you denying my request, Master?”

“You know how to make this stop, Pet.” Optimus reached over his shoulder to stroke his pet’s helm. “You will start again. I know that you can complete this training; it is not without challenge, but it is far from impossible.”

His engine whined. Megatron nodded against Optimus’s neck cabling, and pushed himself to thrust again. Every jerk of his hips burned. Megatron used Optimus’s moans to ground himself. He used the pleasure of his master to drive his thrusts, aching to feel the relief of Optimus’s valve clenching in overload.

As Megatron felt it, he pushed deeper, his knot pressing hard against the rim of Optimus’s port. He ached to pop it through, to find the sweet relief of warmth around his throbbing knot. His legs trembled with the effort it took to obey his orders, his servos holding tighter to Optimus’s pauldrons. Every moment without the promised pleasure was agony.

Without a second thought, Megatron turned his helm and sunk his fangs into Optimus’s neck cables; the resulting scream, along with the tantalizing fuel sliding over his tongue had him bucking into another painful overload.

Fuzzy from overload, Megatron checked his transfluid tanks. They hovered at 43%. He rumbled with relief, knowing that if he could push through two more overloads then he could finish his training.

Megatron was interrupted from his daze by the warmth around his spike leaving him. He groaned, chasing that heat, only for him to be cuffed over the helm.

“I told you that if you bit then the muzzle would be replaced.” Optimus rose on shaky pedes, walking slightly bow legged as he strode over to retrieve the muzzle. As he looped it over Megatron’s helm his lip plates were set in a firm line, terribly unamused by the gaping wound in his neck cables.

The fact that Optimus’s engines were still running hot didn’t escape Megatron’s watchful, though foggy, optic. He leaned into the touch of the muzzle, despite its restrictions. He nuzzled Optimus’s palm, grateful he was allowed to seek physical affection after his faux pas.

“You’re an unruly animal,” Optimus rumbled, swiping his thumb’s sensor pad over Megatron’s lower lip plate. “It is a good thing that I have boundless patience, my pet.”

Megatron let the silence of being muzzled wash over him. He vented out a heavy rush from his engine, and leaned into his master’s machinations. He shuttered his optics, allowing Optimus to move his frame as he desired.

“You’ve done well besides your slip up, pet. I know you have trouble controlling your urges. That is what all of these trainings are for. Perhaps I jumped the gun when I removed the muzzle. We will resume training with it on.” Optimus resumed his position at the breeding bench. He patted his thigh, encouraging Megatron to continue.

Megatron’s eye caught on his master’s valve. Silver fluid streamed from the winking port, cycling down on nothing and looking terribly hungry. The fog of arousal was more motivation than hindrance as he lined up his spike and rolled his hips forward.

The next overload was a blur. Megatron wasn’t sure it even happened; all he could feel was the throb of his knot and the heat sloshing around his spike. The only proof he had was his ever emptying transfluid tank. Transfluid spilled out around his spike as he worked Optimus over, grinding and pushing, his engine growling like a beast.

Another shuddering overload from Optimus had Megatron roaring, his pistons working harder to push him further. His knot bent the rim of Optimus’s valve with every hard thrust. His master was crying out beneath him, his HUD was littered with temperature and hydraulic pressure warnings. Without warning, Optimus’s valve finally gave and his knot popped in. The resulting overload had him bucking and convulsing as charge crackled over his plating, arcing over him and down through their united frames.

As he collapsed atop Optimus, Megatron nestled his face back into the crook between Optimus’s pauldron and his neck. His processor was blank, and his transfluid reserves empty.

He was aware of a servo stroking along the leather of the muzzle, and looked to meet it.

Optimus smiled back, peering over his shoulder at him. “Good pet.”

That, out of everything else, was what really made Megatron relax.

  
  
  
  
  
  
  
  



	2. Aftercare

**Summary for the Chapter:**

> Optimus and Megatron clean up after their scene.

“Easy now,” Optimus said as he helped Megatron down to his knees. He made slow, measured motions to undo the muzzle, and then rubbed the clasp of his collar. “Are you ready for this to come off?”

Megatron didn’t answer right away. Optimus didn’t push, let him heave and vent as much as he needed, before he shook his head. Optimus nodded, and instead stroked along Megatron’s jaw to soothe him. After, he motioned to the inhibitor around Megatron’s spike. “Then I’m going to remove this. It will be uncomfortable.” 

Megatron didn’t get a chance to answer. He hissed his discomfort as the ring released his spike, and all the hydraulic pressure ebbed. His cord was slow to soften, sluggish in its retreat. Megatron let his frame slump forward against Optimus, finally released from what had felt like the harshest punishment of their relationship. 

It hadn’t been, by any means, but his frame cried out for comfort nonetheless.

Which Optimus gave him without a second thought. The Prime curled his arms around Megatron and lifted him, his hands holding Megatron below his hips. Megatron sank into Optimus’s hold like a sparkling. The world was too bright, his processor too empty to process it all. He buried his nasal ridge into Optimus’s throat cables instead. It was just easier that way, inhaling the scent of his master. It smelled like safety. 

At some point Megatron was laid in the wash racks, and Optimus knelt beside him. He whined upon Distance being put between them. As soon as he did, a palm cradled his faceplate. 

“I’m going to get some solvents and that wax you prefer. I won’t be gone long. Are you okay, or do I need to stay a moment longer?”

“I’m fine,” Megatron croaked, his vocalizer popping with static. He floated in and out as he blinked, slow and mostly to be sure what he was seeing was a part of the waking world. He felt buried still, beneath the weight of his own consciousness. He was weighed down, without malice, and still felt as if he were floating. 

Before Megatron could notice the time passing, Optimus returned as promised. Megatron only grunted as he was moved with careful servos. He allowed his frame to be manipulated, letting Optimus wipe away ozone and mechfluids. Before he realized it, he realized the wash rack was raining down upon him, bringing about a fresh awakening. 

“How sore?” Optimus asked, slow to help Megatron to his pedes. 

“Good sore,” Megatron grunted. The solvent washed away some of the fog plaguing his processor. 

“Megatron.”

He grunted again, but guided Optimus’s servo to his spike housing, where his spike was nestled happily inside- without any desire to come out. “Good sore,” he insisted before closing the distance between their frames. Optimus would take care of his vessel; for now what he needed was to be close to his master.

Optimus buffed away the paint transfers and transfluid smears without further questioning. He wiped Megatron down under the solvent, before he finally turned the stream off. Megatron relaxed as he was sat down, still too dazed to protest his frame being manhandled and manipulated. 

Next came the dry wipe down, which Megatron didn’t pay attention to. After, he vented out slowly as Optimus rubbed wax into his aching frame in little circles, slowly bringing him back to full awareness one body part at a time. 

By the time Optimus was done, Megatron felt more at home in his own frame. He tilted his helm up, letting Optimus see the clasps of the collar in a silent bid that he was ready for it to come off. Optimus’s servos were softened by the wax and the buffing cloth, and Megatron found his spark spinning faster as the collar came off. 

He vented out in heavy breaths, before saying, “I truly did not believe I would finish my punishment.”

“But you did,” Optimus said, offering Megatron his servo. He lead Megatron back to their berth, where he laid him down with utmost care, and fetched a pleasant, heavy tarp to drape over the both of them. Optimus curled up behind Megatron, servo reaching over to stroke his helm. “You did well, my dear. I think you’ve earned yourself a treat.”

Megatron ‘hmm’ed and shuttered his optics. “My treat is a well deserved stasis nap.”

“You’ll receive more upon your waking,” Optimus assured him, leaning down to press a kiss to Megatron’s pauldron. “Rest well, dear spark.”

“Do you need anything?” Megatron asked, barely hanging onto consciousness. He knew that Optimus’s main source of aftercare was taking care of his battered frame after an intense scene, but Megatron still needed to hear him say it.

“I’m very happy with our scene and your aftercare,” Optimus assured him. He laid his servo along Megatron’s trim waist, and leaned in to plant another kiss on his neck. “You have given me more than enough.”


End file.
